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Started by cin, December 13, 2021, 07:36:32 PM
Quote from: cin on December 19, 2021, 01:58:12 PMThe amp arrived to me with a loud buzz that's independent of any knob.
Quote from: phatt on December 19, 2021, 09:25:52 PMSet your meter to DC and measure the DC voltage at the speaker terminals.It should read very low DC voltage i.e. less than 1/2 a volt, the less DC the better.
Quote from: cin on December 20, 2021, 12:14:15 PMQuote from: phatt on December 19, 2021, 09:25:52 PMSet your meter to DC and measure the DC voltage at the speaker terminals.It should read very low DC voltage i.e. less than 1/2 a volt, the less DC the better.Thanks for the tip. I did just that and found only -0.004V DC across the speaker terminals with the speaker plugged-in and buzzing. I found that the amp wasn't making any sound at one point and then the PCB shifted and made proper contact with the chassis at the ground plate,
Quote from: cin on December 20, 2021, 12:14:15 PM Or it normal for amps not to work unless they have physical contact with the chassis?Cheers!
Quote from: phatt on December 20, 2021, 09:25:42 PMQ, At any time while the chassis was not contacting the pcb did the amp pass any audio signal?If you can take a picture of the PCB (both sides) and a pic of Chassis as best you can to show what we are looking at might help.
Quote from: phatt on December 27, 2021, 06:17:05 PMIs the Buzz still present with guitar plugged in and the volume knob on guitar set to Zero?Also does the buzz increase as you turn up the gain knob on the amp?Just be aware that a lot of amps will have some residual noise and in a QUITE room near computers, Fluro lights and many other sources of RFI/EMI it will be noticed.If the buzz/hum is louder than your guitar playing then yes there is a major problem, other wise you may have to live with it.